Generation of high-purity human ventral midbrain dopaminergic progenitors for in vitro maturation and intracerebral transplantation

Generation of precisely patterned neural cells from human pluripotent stem cells (hPSCs) is instrumental in developing disease models and stem cell therapies. Here, the authors provide a detailed 16-d protocol for obtaining high-purity ventral midbrain (VM) dopamine (DA) progenitors for intracerebral transplantation into animal models and for in vitro maturation into neurons. They have successfully transplanted such cells into the rat; however, in principle, the cells can be used for transplantation into any animal model, and the protocol is designed to also be compatible with clinical transplantation into humans. They show how to precisely set the balance of patterning factors to obtain specifically the caudal VM progenitors that give rise to DA-rich grafts. By specifying how to perform quality control (QC), troubleshooting, and adaptation of the procedure, this protocol will facilitate implementation in different laboratories and with a variety of hPSC lines. To facilitate the reproducibility of experiments and enable the shipping of cells between centers, the authors present a method for cryopreservation of the progenitors for subsequent direct transplantation or terminal differentiation into DA neurons. This protocol is free of xeno-derived products and can be performed under good manufacturing practice (GMP) conditions.